[INFO] cloning repository https://github.com/echochamber/tinkering
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/echochamber/tinkering" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fechochamber%2Ftinkering", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fechochamber%2Ftinkering'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 8e17f3360b516c74c1388059fa3c708a33ac4b6b
[INFO] documenting echochamber/tinkering against beta-2020-08-29 for beta-1.47-rustdoc-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fechochamber%2Ftinkering" "/workspace/builds/worker-4/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/echochamber/tinkering on toolchain beta-2020-08-29
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-08-29" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/echochamber/tinkering
[INFO] finished tweaking git repo https://github.com/echochamber/tinkering
[INFO] tweaked toml for git repo https://github.com/echochamber/tinkering written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate git repo https://github.com/echochamber/tinkering already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-08-29" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded rustc-demangle v0.1.5
[INFO] [stderr]   Downloaded backtrace v0.3.4
[INFO] [stderr]   Downloaded mio v0.6.11
[INFO] [stderr]   Downloaded futures v0.1.17
[INFO] [stderr]   Downloaded tokio-io v0.1.4
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-08-29" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 52286d69b9ce4a6f758c4143a2097aba74aa33f339edea5ae40c0edc997c1a2b
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "52286d69b9ce4a6f758c4143a2097aba74aa33f339edea5ae40c0edc997c1a2b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "52286d69b9ce4a6f758c4143a2097aba74aa33f339edea5ae40c0edc997c1a2b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "52286d69b9ce4a6f758c4143a2097aba74aa33f339edea5ae40c0edc997c1a2b", kill_on_drop: false }`
[INFO] [stdout] 52286d69b9ce4a6f758c4143a2097aba74aa33f339edea5ae40c0edc997c1a2b
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTDOCFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-08-29" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 30a4f01cc8e3a6d29a21dae02316c81da94fdd3125f0a537f2a5233fe480adb5
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "30a4f01cc8e3a6d29a21dae02316c81da94fdd3125f0a537f2a5233fe480adb5", kill_on_drop: false }`
[INFO] [stderr]     Checking libc v0.2.33
[INFO] [stderr]    Compiling cc v1.0.3
[INFO] [stderr]     Checking cfg-if v0.1.2
[INFO] [stderr]     Checking byteorder v1.1.0
[INFO] [stderr]     Checking rustc-demangle v0.1.5
[INFO] [stderr]     Checking lazycell v0.5.1
[INFO] [stderr]     Checking unicode-width v0.1.4
[INFO] [stderr]     Checking futures v0.1.17
[INFO] [stderr]     Checking vec_map v0.8.0
[INFO] [stderr]     Checking textwrap v0.9.0
[INFO] [stderr]     Checking iovec v0.1.1
[INFO] [stderr]     Checking net2 v0.2.31
[INFO] [stderr]     Checking atty v0.2.3
[INFO] [stderr]     Checking termion v1.5.1
[INFO] [stderr]     Checking clap v2.27.1
[INFO] [stderr]     Checking bytes v0.4.5
[INFO] [stderr]     Checking mio v0.6.11
[INFO] [stderr]    Compiling backtrace-sys v0.1.16
[INFO] [stderr]     Checking tokio-io v0.1.4
[INFO] [stderr]     Checking tokio-core v0.1.10
[INFO] [stderr]     Checking backtrace v0.3.4
[INFO] [stderr]     Checking error-chain v0.11.0
[INFO] [stderr]  Documenting echo-edit v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/main.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(io)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: Compilation failed, aborting rustdoc
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: Could not document `echo-edit`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --crate-type bin --crate-name echo_edit src/main.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi --document-private-items -L dependency=/opt/rustwide/target/debug/deps --extern clap=/opt/rustwide/target/debug/deps/libclap-e26db3c687b96c21.rmeta --extern error_chain=/opt/rustwide/target/debug/deps/liberror_chain-03044896e7b61dd4.rmeta --extern futures=/opt/rustwide/target/debug/deps/libfutures-f22c15f417d1d083.rmeta --extern log=/opt/rustwide/target/debug/deps/liblog-e8073698be3683f7.rmeta --extern termion=/opt/rustwide/target/debug/deps/libtermion-18b12aa748c0ca3a.rmeta --extern tokio_core=/opt/rustwide/target/debug/deps/libtokio_core-d63177b8cbb81046.rmeta --cap-lints=warn --crate-version 0.1.0` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "30a4f01cc8e3a6d29a21dae02316c81da94fdd3125f0a537f2a5233fe480adb5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "30a4f01cc8e3a6d29a21dae02316c81da94fdd3125f0a537f2a5233fe480adb5", kill_on_drop: false }`
[INFO] [stdout] 30a4f01cc8e3a6d29a21dae02316c81da94fdd3125f0a537f2a5233fe480adb5